sound/usb/clock.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Clock domain and sample rate management functions
   4  */
   5
   6 #include <linux/bitops.h>
   7 #include <linux/init.h>
   8 #include <linux/string.h>
   9 #include <linux/usb.h>
  10 #include <linux/usb/audio.h>
  11 #include <linux/usb/audio-v2.h>
  12 #include <linux/usb/audio-v3.h>
  13
  14 #include <sound/core.h>
  15 #include <sound/info.h>
  16 #include <sound/pcm.h>
  17
  18 #include "usbaudio.h"
  19 #include "card.h"
  20 #include "helper.h"
  21 #include "clock.h"
  22 #include "quirks.h"
  23
  24 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
  25                                  bool (*validator)(void *, int), u8 type)
  26 {
  27         void *cs = NULL;
  28
  29         while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
  30                                              cs, type))) {
  31                 if (validator(cs, id))
  32                         return cs;
  33         }
  34
  35         return NULL;
  36 }
  37
  38 static bool validate_clock_source_v2(void *p, int id)
  39 {
  40         struct uac_clock_source_descriptor *cs = p;
  41         return cs->bLength == sizeof(*cs) && cs->bClockID == id;
  42 }
  43
  44 static bool validate_clock_source_v3(void *p, int id)
  45 {
  46         struct uac3_clock_source_descriptor *cs = p;
  47         return cs->bLength == sizeof(*cs) && cs->bClockID == id;
  48 }
  49
  50 static bool validate_clock_selector_v2(void *p, int id)
  51 {
  52         struct uac_clock_selector_descriptor *cs = p;
  53         return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
  54                 cs->bLength == 7 + cs->bNrInPins;
  55 }
  56
  57 static bool validate_clock_selector_v3(void *p, int id)
  58 {
  59         struct uac3_clock_selector_descriptor *cs = p;
  60         return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
  61                 cs->bLength == 11 + cs->bNrInPins;
  62 }
  63
  64 static bool validate_clock_multiplier_v2(void *p, int id)
  65 {
  66         struct uac_clock_multiplier_descriptor *cs = p;
  67         return cs->bLength == sizeof(*cs) && cs->bClockID == id;
  68 }
  69
  70 static bool validate_clock_multiplier_v3(void *p, int id)
  71 {
  72         struct uac3_clock_multiplier_descriptor *cs = p;
  73         return cs->bLength == sizeof(*cs) && cs->bClockID == id;
  74 }
  75
  76 #define DEFINE_FIND_HELPER(name, obj, validator, type)          \
  77 static obj *name(struct usb_host_interface *iface, int id)      \
  78 {                                                               \
  79         return find_uac_clock_desc(iface, id, validator, type); \
  80 }
  81
  82 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
  83                    struct uac_clock_source_descriptor,
  84                    validate_clock_source_v2, UAC2_CLOCK_SOURCE);
  85 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
  86                    struct uac3_clock_source_descriptor,
  87                    validate_clock_source_v3, UAC3_CLOCK_SOURCE);
  88
  89 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
  90                    struct uac_clock_selector_descriptor,
  91                    validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
  92 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
  93                    struct uac3_clock_selector_descriptor,
  94                    validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
  95
  96 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
  97                    struct uac_clock_multiplier_descriptor,
  98                    validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
  99 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
 100                    struct uac3_clock_multiplier_descriptor,
 101                    validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
 102
 103 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
 104 {
 105         unsigned char buf;
 106         int ret;
 107
 108         ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
 109                               UAC2_CS_CUR,
 110                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 111                               UAC2_CX_CLOCK_SELECTOR << 8,
 112                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 113                               &buf, sizeof(buf));
 114
 115         if (ret < 0)
 116                 return ret;
 117
 118         return buf;
 119 }
 120
 121 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
 122                                         unsigned char pin)
 123 {
 124         int ret;
 125
 126         ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
 127                               UAC2_CS_CUR,
 128                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 129                               UAC2_CX_CLOCK_SELECTOR << 8,
 130                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 131                               &pin, sizeof(pin));
 132         if (ret < 0)
 133                 return ret;
 134
 135         if (ret != sizeof(pin)) {
 136                 usb_audio_err(chip,
 137                         "setting selector (id %d) unexpected length %d\n",
 138                         selector_id, ret);
 139                 return -EINVAL;
 140         }
 141
 142         ret = uac_clock_selector_get_val(chip, selector_id);
 143         if (ret < 0)
 144                 return ret;
 145
 146         if (ret != pin) {
 147                 usb_audio_err(chip,
 148                         "setting selector (id %d) to %x failed (current: %d)\n",
 149                         selector_id, pin, ret);
 150                 return -EINVAL;
 151         }
 152
 153         return ret;
 154 }
 155
 156 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
 157                                       int protocol,
 158                                       int source_id)
 159 {
 160         int err;
 161         unsigned char data;
 162         struct usb_device *dev = chip->dev;
 163         u32 bmControls;
 164
 165         if (protocol == UAC_VERSION_3) {
 166                 struct uac3_clock_source_descriptor *cs_desc =
 167                         snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
 168
 169                 if (!cs_desc)
 170                         return 0;
 171                 bmControls = le32_to_cpu(cs_desc->bmControls);
 172         } else { /* UAC_VERSION_1/2 */
 173                 struct uac_clock_source_descriptor *cs_desc =
 174                         snd_usb_find_clock_source(chip->ctrl_intf, source_id);
 175
 176                 if (!cs_desc)
 177                         return 0;
 178                 bmControls = cs_desc->bmControls;
 179         }
 180
 181         /* If a clock source can't tell us whether it's valid, we assume it is */
 182         if (!uac_v2v3_control_is_readable(bmControls,
 183                                       UAC2_CS_CONTROL_CLOCK_VALID))
 184                 return 1;
 185
 186         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 187                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 188                               UAC2_CS_CONTROL_CLOCK_VALID << 8,
 189                               snd_usb_ctrl_intf(chip) | (source_id << 8),
 190                               &data, sizeof(data));
 191
 192         if (err < 0) {
 193                 dev_warn(&dev->dev,
 194                          "%s(): cannot get clock validity for id %d\n",
 195                            __func__, source_id);
 196                 return 0;
 197         }
 198
 199         return !!data;
 200 }
 201
 202 static int __uac_clock_find_source(struct snd_usb_audio *chip, int entity_id,
 203                                    unsigned long *visited, bool validate)
 204 {
 205         struct uac_clock_source_descriptor *source;
 206         struct uac_clock_selector_descriptor *selector;
 207         struct uac_clock_multiplier_descriptor *multiplier;
 208
 209         entity_id &= 0xff;
 210
 211         if (test_and_set_bit(entity_id, visited)) {
 212                 usb_audio_warn(chip,
 213                          "%s(): recursive clock topology detected, id %d.\n",
 214                          __func__, entity_id);
 215                 return -EINVAL;
 216         }
 217
 218         /* first, see if the ID we're looking for is a clock source already */
 219         source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
 220         if (source) {
 221                 entity_id = source->bClockID;
 222                 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_2,
 223                                                                 entity_id)) {
 224                         usb_audio_err(chip,
 225                                 "clock source %d is not valid, cannot use\n",
 226                                 entity_id);
 227                         return -ENXIO;
 228                 }
 229                 return entity_id;
 230         }
 231
 232         selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
 233         if (selector) {
 234                 int ret, i, cur;
 235
 236                 /* the entity ID we are looking for is a selector.
 237                  * find out what it currently selects */
 238                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 239                 if (ret < 0)
 240                         return ret;
 241
 242                 /* Selector values are one-based */
 243
 244                 if (ret > selector->bNrInPins || ret < 1) {
 245                         usb_audio_err(chip,
 246                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 247                                 __func__, selector->bClockID, ret);
 248
 249                         return -EINVAL;
 250                 }
 251
 252                 cur = ret;
 253                 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
 254                                                visited, validate);
 255                 if (!validate || ret > 0 || !chip->autoclock)
 256                         return ret;
 257
 258                 /* The current clock source is invalid, try others. */
 259                 for (i = 1; i <= selector->bNrInPins; i++) {
 260                         int err;
 261
 262                         if (i == cur)
 263                                 continue;
 264
 265                         ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
 266                                 visited, true);
 267                         if (ret < 0)
 268                                 continue;
 269
 270                         err = uac_clock_selector_set_val(chip, entity_id, i);
 271                         if (err < 0)
 272                                 continue;
 273
 274                         usb_audio_info(chip,
 275                                  "found and selected valid clock source %d\n",
 276                                  ret);
 277                         return ret;
 278                 }
 279
 280                 return -ENXIO;
 281         }
 282
 283         /* FIXME: multipliers only act as pass-thru element for now */
 284         multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
 285         if (multiplier)
 286                 return __uac_clock_find_source(chip, multiplier->bCSourceID,
 287                                                 visited, validate);
 288
 289         return -EINVAL;
 290 }
 291
 292 static int __uac3_clock_find_source(struct snd_usb_audio *chip, int entity_id,
 293                                    unsigned long *visited, bool validate)
 294 {
 295         struct uac3_clock_source_descriptor *source;
 296         struct uac3_clock_selector_descriptor *selector;
 297         struct uac3_clock_multiplier_descriptor *multiplier;
 298
 299         entity_id &= 0xff;
 300
 301         if (test_and_set_bit(entity_id, visited)) {
 302                 usb_audio_warn(chip,
 303                          "%s(): recursive clock topology detected, id %d.\n",
 304                          __func__, entity_id);
 305                 return -EINVAL;
 306         }
 307
 308         /* first, see if the ID we're looking for is a clock source already */
 309         source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
 310         if (source) {
 311                 entity_id = source->bClockID;
 312                 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_3,
 313                                                                 entity_id)) {
 314                         usb_audio_err(chip,
 315                                 "clock source %d is not valid, cannot use\n",
 316                                 entity_id);
 317                         return -ENXIO;
 318                 }
 319                 return entity_id;
 320         }
 321
 322         selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
 323         if (selector) {
 324                 int ret, i, cur;
 325
 326                 /* the entity ID we are looking for is a selector.
 327                  * find out what it currently selects */
 328                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 329                 if (ret < 0)
 330                         return ret;
 331
 332                 /* Selector values are one-based */
 333
 334                 if (ret > selector->bNrInPins || ret < 1) {
 335                         usb_audio_err(chip,
 336                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 337                                 __func__, selector->bClockID, ret);
 338
 339                         return -EINVAL;
 340                 }
 341
 342                 cur = ret;
 343                 ret = __uac3_clock_find_source(chip, selector->baCSourceID[ret - 1],
 344                                                visited, validate);
 345                 if (!validate || ret > 0 || !chip->autoclock)
 346                         return ret;
 347
 348                 /* The current clock source is invalid, try others. */
 349                 for (i = 1; i <= selector->bNrInPins; i++) {
 350                         int err;
 351
 352                         if (i == cur)
 353                                 continue;
 354
 355                         ret = __uac3_clock_find_source(chip, selector->baCSourceID[i - 1],
 356                                 visited, true);
 357                         if (ret < 0)
 358                                 continue;
 359
 360                         err = uac_clock_selector_set_val(chip, entity_id, i);
 361                         if (err < 0)
 362                                 continue;
 363
 364                         usb_audio_info(chip,
 365                                  "found and selected valid clock source %d\n",
 366                                  ret);
 367                         return ret;
 368                 }
 369
 370                 return -ENXIO;
 371         }
 372
 373         /* FIXME: multipliers only act as pass-thru element for now */
 374         multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
 375                                                       entity_id);
 376         if (multiplier)
 377                 return __uac3_clock_find_source(chip, multiplier->bCSourceID,
 378                                                 visited, validate);
 379
 380         return -EINVAL;
 381 }
 382
 383 /*
 384  * For all kinds of sample rate settings and other device queries,
 385  * the clock source (end-leaf) must be used. However, clock selectors,
 386  * clock multipliers and sample rate converters may be specified as
 387  * clock source input to terminal. This functions walks the clock path
 388  * to its end and tries to find the source.
 389  *
 390  * The 'visited' bitfield is used internally to detect recursive loops.
 391  *
 392  * Returns the clock source UnitID (>=0) on success, or an error.
 393  */
 394 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int protocol,
 395                               int entity_id, bool validate)
 396 {
 397         DECLARE_BITMAP(visited, 256);
 398         memset(visited, 0, sizeof(visited));
 399
 400         switch (protocol) {
 401         case UAC_VERSION_2:
 402                 return __uac_clock_find_source(chip, entity_id, visited,
 403                                                validate);
 404         case UAC_VERSION_3:
 405                 return __uac3_clock_find_source(chip, entity_id, visited,
 406                                                validate);
 407         default:
 408                 return -EINVAL;
 409         }
 410 }
 411
 412 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
 413                               struct usb_host_interface *alts,
 414                               struct audioformat *fmt, int rate)
 415 {
 416         struct usb_device *dev = chip->dev;
 417         unsigned int ep;
 418         unsigned char data[3];
 419         int err, crate;
 420
 421         if (get_iface_desc(alts)->bNumEndpoints < 1)
 422                 return -EINVAL;
 423         ep = get_endpoint(alts, 0)->bEndpointAddress;
 424
 425         /* if endpoint doesn't have sampling rate control, bail out */
 426         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 427                 return 0;
 428
 429         data[0] = rate;
 430         data[1] = rate >> 8;
 431         data[2] = rate >> 16;
 432         err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 433                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 434                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 435                               data, sizeof(data));
 436         if (err < 0) {
 437                 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
 438                         iface, fmt->altsetting, rate, ep);
 439                 return err;
 440         }
 441
 442         /* Don't check the sample rate for devices which we know don't
 443          * support reading */
 444         if (snd_usb_get_sample_rate_quirk(chip))
 445                 return 0;
 446         /* the firmware is likely buggy, don't repeat to fail too many times */
 447         if (chip->sample_rate_read_error > 2)
 448                 return 0;
 449
 450         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 451                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 452                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 453                               data, sizeof(data));
 454         if (err < 0) {
 455                 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
 456                         iface, fmt->altsetting, ep);
 457                 chip->sample_rate_read_error++;
 458                 return 0; /* some devices don't support reading */
 459         }
 460
 461         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 462         if (crate != rate) {
 463                 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
 464                 // runtime->rate = crate;
 465         }
 466
 467         return 0;
 468 }
 469
 470 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 471                               int altsetting, int clock)
 472 {
 473         struct usb_device *dev = chip->dev;
 474         __le32 data;
 475         int err;
 476
 477         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 478                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 479                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 480                               snd_usb_ctrl_intf(chip) | (clock << 8),
 481                               &data, sizeof(data));
 482         if (err < 0) {
 483                 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
 484                          iface, altsetting, err);
 485                 return 0;
 486         }
 487
 488         return le32_to_cpu(data);
 489 }
 490
 491 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 492                               struct usb_host_interface *alts,
 493                               struct audioformat *fmt, int rate)
 494 {
 495         struct usb_device *dev = chip->dev;
 496         __le32 data;
 497         int err, cur_rate, prev_rate;
 498         int clock;
 499         bool writeable;
 500         u32 bmControls;
 501
 502         /* First, try to find a valid clock. This may trigger
 503          * automatic clock selection if the current clock is not
 504          * valid.
 505          */
 506         clock = snd_usb_clock_find_source(chip, fmt->protocol,
 507                                           fmt->clock, true);
 508         if (clock < 0) {
 509                 /* We did not find a valid clock, but that might be
 510                  * because the current sample rate does not match an
 511                  * external clock source. Try again without validation
 512                  * and we will do another validation after setting the
 513                  * rate.
 514                  */
 515                 clock = snd_usb_clock_find_source(chip, fmt->protocol,
 516                                                   fmt->clock, false);
 517                 if (clock < 0)
 518                         return clock;
 519         }
 520
 521         prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
 522         if (prev_rate == rate)
 523                 goto validation;
 524
 525         if (fmt->protocol == UAC_VERSION_3) {
 526                 struct uac3_clock_source_descriptor *cs_desc;
 527
 528                 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
 529                 bmControls = le32_to_cpu(cs_desc->bmControls);
 530         } else {
 531                 struct uac_clock_source_descriptor *cs_desc;
 532
 533                 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
 534                 bmControls = cs_desc->bmControls;
 535         }
 536
 537         writeable = uac_v2v3_control_is_writeable(bmControls,
 538                                                   UAC2_CS_CONTROL_SAM_FREQ);
 539         if (writeable) {
 540                 data = cpu_to_le32(rate);
 541                 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
 542                                       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 543                                       UAC2_CS_CONTROL_SAM_FREQ << 8,
 544                                       snd_usb_ctrl_intf(chip) | (clock << 8),
 545                                       &data, sizeof(data));
 546                 if (err < 0) {
 547                         usb_audio_err(chip,
 548                                 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
 549                                 iface, fmt->altsetting, rate, err);
 550                         return err;
 551                 }
 552
 553                 cur_rate = get_sample_rate_v2v3(chip, iface,
 554                                                 fmt->altsetting, clock);
 555         } else {
 556                 cur_rate = prev_rate;
 557         }
 558
 559         if (cur_rate != rate) {
 560                 if (!writeable) {
 561                         usb_audio_warn(chip,
 562                                  "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
 563                                  iface, fmt->altsetting, rate, cur_rate);
 564                         return -ENXIO;
 565                 }
 566                 usb_audio_dbg(chip,
 567                         "current rate %d is different from the runtime rate %d\n",
 568                         cur_rate, rate);
 569         }
 570
 571         /* Some devices doesn't respond to sample rate changes while the
 572          * interface is active. */
 573         if (rate != prev_rate) {
 574                 usb_set_interface(dev, iface, 0);
 575                 snd_usb_set_interface_quirk(dev);
 576                 usb_set_interface(dev, iface, fmt->altsetting);
 577                 snd_usb_set_interface_quirk(dev);
 578         }
 579
 580 validation:
 581         /* validate clock after rate change */
 582         if (!uac_clock_source_is_valid(chip, fmt->protocol, clock))
 583                 return -ENXIO;
 584         return 0;
 585 }
 586
 587 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 588                              struct usb_host_interface *alts,
 589                              struct audioformat *fmt, int rate)
 590 {
 591         switch (fmt->protocol) {
 592         case UAC_VERSION_1:
 593         default:
 594                 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 595
 596         case UAC_VERSION_3:
 597                 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
 598                         if (rate != UAC3_BADD_SAMPLING_RATE)
 599                                 return -ENXIO;
 600                         else
 601                                 return 0;
 602                 }
 603         /* fall through */
 604         case UAC_VERSION_2:
 605                 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
 606         }
 607 }
 608